Sensitivity Analysis and Optimization of GaSb induced Double- Gate Junctionless Vertical TFET for Gas Sensing Application

This paper endeavors to design N⁺ doped GaSb based double gate junctionless vertical TFET by Silvaco TCAD simulation tool, and evaluate the electrical properties of the device for application of gas sensing. The proposed device has effective electrostatic control owing to the gate stack of High-K (HfO2) with (SiO2) and the two-side gate metal electrodes. The double-sided gate vertical design shows superior performance performs in terms of gate controllability than traditional TFETs for band-to-band tunneling (BTBT). Here, ammonia gas is investigated with cobalt and molybdenum metals as the gate electrode while hydrogen gas is investigated with palladium as the gate electrode. P+ pockets are created close to the source field using appropriate work function values for the above mentioned metals. In addition, the inclusion of a GaSb layer between the source-channel interface lowers the tunneling barrier and increases the performance of the device by decreasing the energy bandgap from 1.1 eV to 0.67 eV. The simulation results shows better sensitivity for Molybdenum, Cobalt and Palladium as 4.24× 10³, 3.86× 10³, and 8.92× 10² respectively and the Ion/Ioff ratios are (1× 10⁶, 1.50× 10⁹, and 1.36× 10¹²) respectively. This paper also discusses the electrical properties of the simulated device such as electric field and surface potential distribution.